One-step fabrication of nanowire-grid polarizers using liquid-bridge-mediated nanotransfer molding.

Ag nanowire-grid polarizers (NWGPs) were prepared by a one-step fabrication method, called liquid-bridge-mediated nanotransfer molding (LB-nTM). LB-nTM is a new direct nano-patterning method based on the direct transfer of various materials from a mold to a substrate via liquid layer. We fabricated NWGPs with Ag nanowire arrays (81 nm parallel lines and 119 nm spaces) on 2.5 in. transparent substrates by LB-nTM using an Ag nanoparticle solution. The maximum and minimum transmittances of the Ag NWGP at 800 nm were 80% and 10%, respectively.

The facile fabrication of a wire-grid polarizer by reversal rigiflex printing.

Wire-grid polarizers (WGPs) can be fabricated easily by reversal rigiflex printing. Metal films with gratings were fabricated on a transparent glass substrate by transfer printing with a metal coated rigiflex mold, and the transferred metal gratings were then etched slightly to eliminate the residual layer. As a result, aligned metal wires (70 nm line/space width, 120 nm height) occupying an area of 3.0 cm x 2.5 cm were obtained. The maximum and minimum transmittances of a WGP replicated from a commercial Moxtek polarizer at 800 nm were 85% and 27%, respectively.

Gold nanocones fabricated by nanotransfer printing and their application for field emission.

Arrays of gold nanocones have been fabricated by the nanotransfer printing (nTP) method and we have utilized these nanocones for field emission. By the nature of the printing, any shape of metal structure can be fabricated only at desired locations and a step-and-repeat process, which enables large-area fabrication, is possible. We demonstrate step-and-repeat printing with gold nanocone patterns occupying an area of 9 mm × 8 mm.

Anisotropic rupture of polymer strips driven by Rayleigh instability.

We demonstrate that the separated polymer strips of micro- and sub-micro-length-scales rupture anisotropically along the strip direction, resulting in the formation of distinctly observable, regularly spaced polymer drops. The wavelength of the polymer drops and the surface tension dependence of the rupture behavior are found to be well represented by a relationship derived on the basis of Rayleigh instability. The period is proportional to the square root of the cross-sectional area of the strip and the proportionality constant depends on the contact angle. The rupture of polymer strips into polymer blocks instead of drops, which result when annealed with physically confining walls in place, is found to be well described by the same relationship.

Formation of regular nanoscale undulations on a thin polymer film imprinted by a soft mold.

We observed the formation of regular nanoscale undulations on a polystyrene film when imprinted by a soft poly(dimethylsiloxane) mold above the polymer's glass transition temperature. The shape of the wave was reminiscent of a buckling wave frequently observed for a metal film supported on an elastomeric substrate. We derived a simple theoretical model based on an anisotropic buckling of the polymer film rigidly bound to a substrate, which agrees well with the experiment.